Mock model object without setters

I'm implementing tests on my Android app and I want to do unit tests on a model. The problem is that I do not have setters as the model is created with Realm or by parsing a CSV file (witch univocity csv parser).
So, how could I create a mocked object with valid values? I have something like that:

public class Content {

private String title;
private String description;

...
}

How could I generate a mocked Content object with a title and description data?